There has been known a hybrid vehicle power transmitting apparatus including a differential mechanism for distributing an output of an engine, such as an internal combustion engine to a power transmitting path between a first electric motor and drive wheels, a differential-action limiting device that limits a differential action of the differential mechanism or canceling such a differential action, and a second electric motor connected to a power transmitting apparatus extending from the differential mechanism to the drive wheels. For instance, Patent Publication 1 (Japanese Patent Application Publication No. 2006-46386) discloses in FIG. 1 such a hybrid vehicle power transmitting apparatus. With a control device for the hybrid vehicle power transmitting apparatus, if a need for warming up an exhaust system is determined, such as for instance a catalyst of the engine, the engine is driven at a given engine warm-up rotation speed, while the differential mechanism is placed under a differential state enabling a differential action to be initiated.
With the control device for the hybrid vehicle power transmitting apparatus disclosed in Patent Publication 1, it will suffice for an engine rotation speed not to be bound with a vehicle speed due to the differential action of the differential mechanism. This will be effective for facilitating the warm-up of the engine and an exhaust system thereof. However, the other component parts than those including the engine and the exhaust system thereof, i.e., for instance, the component parts of the hybrid vehicle power transmitting apparatus involving the differential mechanism are required to warm up, for allowing lubricating oil to have appropriate viscosity or the like. Speeding up such a warm-up operation leads to improvement in fuel consumption as a whole. However, the control device, disclosed in Patent Publication 1, does not necessarily have such an effect of facilitating the warm-up of the hybrid vehicle power transmitting apparatus.